Samples cut short by other samples

Hi chaps.

Just got myself a Ren. Noticed straight away that if I lay down some samples then try and overdub using the same program it cuts the samples short if I try and play them at the same time as ones I've already laid.

Also is there a quick way to map the same sample across the 16 pads each in a different key. Pretty sure my 2000xl used to be able to do this at the click of a button.

Thanks for help in advance.

Foster

gotta switch mono to poly

Ah yes. Thanks. Are there any good videos you know of that really dig into how to use it? Those university ones just seem to plough through without really showing you how to do things.